The remarkable accuracy of cell division in E. coli and related bacteria is partially regulated by the Minprotein system, which prevents division near the cell ends by oscillating spatially from pole to pole. The scientist has recently developed a complete model of the Min system, using only known properties of the proteins, which accurately reproduces the observed oscillations and predicts a finite nucleotide exchange rate for the MinD protein of around one second, a number that has since been experimentally verified to a high degree of accuracy. This proposal concerns efforts to develop particle-level simulations in rod-shaped cells, to capture for the first time the helical polymer dynamics of the Min proteins. In addition, the scientist intends to extend the model to round cells, to determine whether Min oscillations can spontaneously select the long axis of the cell to define the division plane in cocci in the presence of statistical fluctuations. These particle-level simulations provides a starting point for a general understanding of how prokaryotes and eukaryotes can use a reaction-diffusion protein system to target proteins to different locations and to detect their own geometry, and will have broad applications at the expanding interface between large-scale computation and the microscale biology of protein interactions. In order to understand the mechanism behind E. coli's incredible division accuracy, the scientist will undertake experiments incorporating computational results to study the effects of changes in concentration on oscillation period and division accuracy. The theoretical work will be performed in Dr. Ned Wingreen's lab at Princeton University, with experimental resources and training provided by Dr. Bonnie Bassler at Princeton University.